better idea on the color guns. Leave the damage as is, remove tap fire on the red rifle (this is a mandatory). Increase the photon rifles clip capacity to 24. That way the red and green gun will be par with the photon, but the photon will be able to shoot for longer amounts of time giving the user more time shooting before reloading.
Another thing i forgot to mention, the red and green guns destroy the purpose of the plasma chaingun and gatling gun. I propose increase the clip size of plasma chaingun to 54 and chain gun to 30. This way as the current red rifile will beat a plasma in a head on duel thanks to damage (yes the plasma chaingun fires faster tap fire). The plasma will be givin the ability to provide 3x the amount of fire power as the red rifle before reloading. Even if the red rifle tap fire was nerfed, it would still be able to compete with the plasma chaingun thanks to the 6 damage on the red gun. I have no clue about the gatling gun, i am saving for it though.

Does that sound reasonable?